BILLINGS, Mont. (AP) — Shovelful by shovelful, investigators sifted through the charred remnants of a Montana home where four generations of a family were killed as they gathered for Sunday dinner, searching for evidence that might help explain what happened and why. This was reported by Qazaqyia.kz citing Associated Press.

Alan Smith, 44, killed his grandmother, his parents, his younger sister and her children before dying of a self-inflicted gunshot wound just after police arrived, authorities said. Multiple fires were set inside the suburban home on the outskirts of Billings. Smith had lived there before being asked to move out weeks earlier, according to accounts from police and surviving relatives.

“There’s many questions that will come from this investigation,” Yellowstone County Sheriff Kent O’Donnell said during a news conference Wednesday. “Some of those questions we probably won’t ever be able to answer, because all the parties that will have those answers are not here to answer them for us.”

The victims included Owen and Chloe Ireland and their stepsiblings, Landon and Charlotte Ghekiere. Owen, 13, was described by his father as the “perfect big brother” and Chloe’s protector. Landon, 15, planned to get his driver’s license this week. Charlotte, 12, was a lover of nature, particularly insects, said Jennifer Mercer, a neighbor and family friend.

A candlelight vigil was planned Thursday night.

The attack happened at the home of Smith’s parents: Dana Smith, who was retired from the Air Force and Boeing, and Barb Smith, a retired teacher.

The Smith family was originally from the Seattle area. Brad Ireland, the father of Owen and Chloe, said that after he and Megan Ghekiere divorced six years ago, she moved to Montana with their children. That’s where she met the man who would become her second husband, Adam Ghekiere, who was at work when the shooting occurred.

Her parents soon followed to Billings, buying a house near their daughter, and her brother moved in. Police had not been called to the home before and had no previous contact with Alan Smith, the sheriff said.

Megan Ghekiere, 39, worked in healthcare, Mercer said. The eighth victim was Dana’s mother, Evelyn Smith, 92, who used a wheelchair and lived in a nearby retirement community.

O’Donnell said Smith showed up in the neighborhood at 5:49 p.m. Sunday, and just after 6 p.m., one of the females in the home called 911. He said he couldn’t confirm who made it. But Mercer identified the caller as 12-year-old Charlotte.